KR100777702B1 - Flat panel display and driving method thereof - Google Patents

Abstract

The present invention relates to a flat panel display and a driving method thereof. According to the present invention, a flat panel display device for receiving and processing a display signal output from a graphic source unit via a serial bus, wherein the graphic source unit is configured to display display characteristic information of the flat panel in a flat panel display module via a serial bus. By fetching and analyzing, a display signal of a corresponding new standard can be output, wherein the display characteristic information of the flat panel is the graphic source in response to a user inputting predetermined data using a predetermined program. Not only can it be changed by a predetermined signal output from the unit to the serial bus, but it can also be changed by the user inputting predetermined data using a predetermined key provided outside the flat panel display.

A basic configuration of a flat panel display device according to an embodiment of the present invention includes a graphic source including a graphic source unit, and a flat panel display module including a connector, a D / A converter, a memory unit, and a timing controller.

Flat Panel Display, LCD, DDC, Signal Specifications, Blanking, Gamma, Serial Bus

Description

Flat panel display device and driving method thereof {FLAT PANEL DISPLAY AND DRIVING METHOD THEREOF}

1 is a block diagram illustrating an overall configuration of a conventional flat panel display module.

2 is a block diagram illustrating a graphic source unit and a flat panel display module according to an exemplary embodiment of the present invention.

3 is an example of a display signal generated in the graphic source unit according to the related art.

4 is an example of a display signal generated in the graphic source unit according to an embodiment of the present invention.

5 is a diagram illustrating a gamma change when using an option board according to the related art.

6 is a diagram illustrating a gamma change when adjusting display characteristics through a serial bus according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

300: PC main unit 410: DVI or D-SUB connector

310: graphic source unit 420: D / A conversion unit

400: flat panel display module 430: memory unit                 

440: timing control unit

The present invention relates to a flat panel display and a driving method thereof, and more particularly, to a driving device for driving a flat panel display and a driving method thereof.

Typical flat panel display devices that are commercially available include liquid crystal displays (LCDs) and plasma display panels (PDPs). In addition, development of EL (Electro Luminescence) displays is in progress. .

A flat panel display module is usually composed of a flat panel in which cells are arranged in a matrix between two glass substrates, a PCB module for driving the flat panel, and a case for protecting and integrating them.

On the other hand, as shown in the overall circuit configuration of the conventional flat panel display module shown in Figure 1, the PCB module for driving the flat panel 40 is typically R, G, B image data and synchronization signals from the outside, such as a PC And control the image data and various types according to the structure of the flat panel 40 by processing by a timing controller (T-con: Timing-controller), which is a custom integrated circuit (IC) in the form of a flat pin grid array (FPGA). A main PCB 10 that processes and generates a signal, a low driver 20 supplying a scanning signal to a low signal line according to a low driver control signal 50 and a power source 51 received from the main PCB 10, and a main The column driver 30 receives the image data and the control signal 60 and the gray voltage 61 processed by the PCB 10 and supplies them to the flat panel 40.

However, the conventional driving circuit implemented on the main PCB 10 has a masking timing setting method in which timing and various input driving interface conditions are limited to specifications set to match the panel. In addition, it is not possible to modify the timing or driving of user condition and input condition change of display source and monitor products. That is, even in a driveable range, it is impossible to flexibly support the optimization of display characteristics unless the driving apparatus processes hardware options. This is because the input condition of the flat panel display basically has an input timing condition in the VESA specification. The graphic source side controls the panel driving based on the DDC (Digital Data Communication) information stored in the flat panel display module. Generate and display a digital interface timing control signal. In addition, the flat panel display monitors on the market are set with gamma voltage and various power supplies for gray separation.

According to the related art, by adding an option board, the user can check and adjust the screen display state by the OSD (On Screen Display) function or adjust the hardware directly, such as gamma, flicker voltage, brightness, scaling, and frame rate. Control, I / O format, etc. can be adjusted. However, only by this function, the optimal display can be driven by changing the input / output (I / O) timing (change of drive frequency or minimum optimum blanking time) on the flat panel drive circuit. In addition, by processing the standard signal through the additional circuit in the graphic source (Graphic Source), it is possible to change the driving frequency or the minimum optimum blanking time as described above under the optimum conditions, so that it is a very good driving environment. In addition, since the I / O format must satisfy the condition that the general display standard must be satisfied, the risk of change is very high, no matter how good the condition is.

In addition, especially for monitors, an interface is required to drive different I / O formats of the display source, and if the frame frequency or the number of blanking intervals is different, an additional system capable of FRC (Frame Rate Control) adjustment is possible. The board must be supported by an optional board, such as an A / D board or a D / D board, which also has the limitation of the I / O format of the flat panel display and cannot use 100% of the efficiency of the display product. Jitter caused by the option board or the interface condition between the two sides is not well matched, which adversely affects the image quality, and thus does not contribute to optimization of the characteristics of the monitor product.

As mentioned above, the fixedness of the flat panel display is caused by a different display method from the CRT (Cathode Ray Tube) display. In the case of the CRT, the frame frequency can be driven very widely from 40 Hz to 85 Hz. The driving method is to be fixed by the characteristics of the panel. In other words, if the frame frequency is optimized at the current panel characteristics of 60Hz, the driving conditions are naturally optimized at 60Hz. Also, not all graphics cards or display sources conform to the VESA specification, which may cause slight variations depending on the vendor, providing slightly different data than standard timing. Therefore, if the optimum driving condition timing of the flat panel should be different from the VESA standard signal, or if the standard signal is slightly different according to the vendor, an additional option board is used to adjust this flexible timing. This alone, as mentioned above, is insufficient and its cost is very high.

In addition, the basis of the Besa display input timing is a CRT reference, which scans a blanking time (horizontal sync signal, back porch, front porch) and one frame after returning to the next line after scanning the electron beam. The blanking time (vertical sync signal, back porch, front porch) is specified by the frame frequency for returning from the last position to the beginning. However, the flat panel driving method is not a scanning method but an active matrix method. Since the retrace time after the last display signal of a line or frame is used, unlike the CRT, only the blanking time of the minimum pixel (when horizontal return) or line (when vertical retrace) is required. In addition, the use of an optional board such as an A / D board increases the operating frequency due to unnecessary blanking time in the Besa condition, and the blanking time is long and unstable, and the interface process or I / O becomes unstable. Driving conditions also become quite unstable. Therefore, it is necessary to reduce the blanking time as described above so that the flat panel can be driven at the optimum driving timing condition, so that the display characteristics are stabilized and the reliability is also improved.

In addition, display characteristics may sometimes need to be adjusted differently according to product variations or the user's environment and conditions. In the case of such flat panel monitor products, it has conventionally been an optimal driving condition fixed to the characteristics of the flat panel, and has to be adjusted by an additional option board or interface board. However, in the case of changing the fixed optimum driving conditions to the characteristics of the flat panel by adjusting the gamma, contrast, brightness, flicker, and other display characteristics, A / When using a D board or an option board, the cladding is made to fit in the form of cutting the upper and lower gradations, and there is a problem that the flat panel characteristics cannot be used at 100% efficiency.

Therefore, there is a need for a driving method that eliminates the increase in cost and the like caused by the use of the option board as described above, as well as suppresses the occurrence of jitter or the like due to the mismatch of interface conditions. That is, digital information about the gamma, flicker voltage, luminance values, etc., which can be adjusted by the user, as well as information on the operating frequency, such as resolution information, vertical frequency, horizontal frequency of the video signal, and main frequency of the video signal, is displayed. There is a need to be flexible between changing FRC, I / O format, and other display characteristic information by enabling sharing among panel display modules and updating by users. In particular, the signal output from the graphic source can be a video signal whose blanking time is changed according to the definition of the user in addition to the standard standard signal to the frequency of the video signal, so that it is suitable for driving the flat panel display device. It is necessary to make the best use of it.

Therefore, the object of the present invention is to store and share I / O timing and other display characteristics within the drive, and to adjust and upload using a serial bus that functions as a Besa standard DDC without additional option boards. The present invention provides a flat panel display device having a wide and flexible interface and a driving method thereof.

In order to achieve such a technical problem, a flat panel display device according to one aspect of the present invention is a flat panel display device,
Digital image information and control signals are directly received from a graphic source through a serial bus, and digital screen information and control signals suitable for panel characteristics are generated to display a screen.

In addition, a flat panel display device according to another aspect of the present invention is a flat panel display device,
A memory unit for storing digital display information directly input from a graphic source via a serial bus;
A timing controller which extracts display information suitable for the corresponding flat panel from the memory unit based on the digital display information received from the graphic source and outputs driving signals;
A data driver configured to output an image signal to a data line based on a plurality of signals received from the timing controller; And
And a scan driver configured to output a control signal to a gate line based on the plurality of signals received from the timing controller.
The digital display information may include a plurality of types of signals suitable for a plurality of flat panels.

The digital display information may be changed by a predetermined signal outputted from the graphic source to the serial bus according to a predetermined data input using a predetermined program.

The digital display information may be changed by a user inputting predetermined data using a predetermined key provided outside the flat panel display.

Accordingly, in a flat panel display device that receives and processes a display signal output from a graphic source unit through a serial bus, the graphic source unit fetches display characteristic information of the flat panel from a flat panel display module through a serial bus. By analyzing, it is possible to output a display signal of a corresponding new standard, wherein the display characteristic information of the flat panel is supplied by the graphic source unit in response to a user inputting predetermined data using a predetermined program. Not only can it be changed by a predetermined signal output to the serial bus, but it can also be changed by a user inputting predetermined data using a predetermined key provided outside the flat panel display.

In addition, a method of driving a flat panel display device according to an aspect of the present invention comprises the steps of: storing digital display information directly input from a graphic source via a serial bus;
Extracting display information suitable for a flat panel based on the digital display information received from the graphic source and outputting driving signals;
Outputting an image signal to a data line based on the driving signals; And
And outputting a control signal to a gate line based on the driving signals.

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Hereinafter, a detailed configuration and operation of a flat panel display device according to a preferred embodiment in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, a basic configuration of a liquid crystal display (flat panel display) according to an embodiment of the present invention includes a graphic source 300 including a graphic source unit 310 and a connector 410. And a liquid crystal panel display module 400 including a D / A converter 420, a memory 430, and a timing controller 440. Here, in the liquid crystal display device according to the embodiment of the present invention, all the functions of the conventional option board can be realized, and even if the option board is removed, further functions can be realized, thereby contributing to the cost down. In addition, although the option board is not required to be employed as in the conventional configuration, even if it is adopted, there is no problem in realizing all functions according to the features of the present invention.                     

The graphic source unit 310 is a system for outputting a PC main body or other image signals, that is, a part of the graphic source 300, and corresponds to an apparatus for generating and outputting a synchronization signal, a graphic signal, and other control signals. In particular, by fetching and analyzing the display characteristic information of the liquid crystal panel (flat panel) from the liquid crystal panel display module via the serial bus, a display signal of a corresponding new standard is output.

The connector 410 is a serial bus connector such as DVI or D-SUB for receiving a display signal output from the graphic source unit 310 of the graphic source 300 such as a PC main body and transmitted through predetermined cables 311 and 312. Say 410.

The D / A converter 420 converts predetermined screen display information included in the display characteristic information of the liquid crystal panel stored in the memory unit 430 into analog. That is, screen display information, such as gamma, flicker voltage, and luminance, which should be supplied as analog voltage by D / A conversion among the display characteristic information of the liquid crystal panel which can be adjusted by the user, is input as digital data value and converted into analog voltage. It is converted and supplied to each corresponding circuit of the PCB module. Here, the above series of operations are performed under the control of the timing controller 440 as in the operation of the general liquid crystal display.

The memory unit 430 stores display characteristic information of a flat panel that can be changed by the user, and is shared with the graphic source unit 310. Here, the display characteristic information of the liquid crystal panel is information on the standard of the liquid crystal panel, and only information about resolution information for driving the liquid crystal panel and operating frequency information such as vertical frequency, horizontal frequency, and main frequency of the image signal for driving the liquid crystal panel. Rather, it refers to digital information on gamma, flicker voltage, luminance values, etc., which can be adjusted by the user.

The timing controller 440 receives a display signal output from the graphic source unit 310 through a serial bus and performs arithmetic processing to output a display signal for driving the liquid crystal panel. That is, display signals of the liquid crystal panel such as image signals and control signals corresponding to the display characteristic information of the liquid crystal panel are output and supplied to the corresponding circuits of the PCB module.

The operation of the liquid crystal display according to the exemplary embodiment of the present invention having such a structure will be described in detail.

First, in the case of CRT, the frame frequency can be driven very broadly from 40Hz to 85Hz, whereas the driving method of the liquid crystal panel display is fixed by the characteristics of the panel. If it is optimized, the driving conditions of the timing controller 440 and the like are also optimized under the condition of 60 Hz. By the way, the display of the conventional monitor so far is received by the liquid crystal panel display module 400 that the signal output from the graphic source 300 is fixed to a standard signal such as VESA, by arithmetic processing of the option board and the timing controller. Although the FRC or I / O format may be adjusted and output, the signal output from the graphic source 300 does not allow the FRC or I / O format to be adjusted. In particular, the blanking is elongated. Since time is only needed for the CRT scanning method and not required for a display such as an active matrix method by digital signal processing as in a liquid crystal panel display, it is advantageous to drive the liquid crystal panel if it is removed to the maximum.

 Accordingly, in the liquid crystal display according to the exemplary embodiment of the present invention, the signal output from the graphic source 300 without the option board itself may not only adjust the FRC or I / O format, but also adjust the blanking time. The operation process is as follows.

Operation of the liquid crystal display according to the exemplary embodiment of the present invention as shown in FIG. 2 is as follows. First, a liquid crystal panel display module (or monitor) 400 connected to a graphic source 300 such as a PC main body and a predetermined cable 311 and 312 through a DVI or D-SUB connector 410 for overall operation. When the predetermined power is installed, the display characteristic information of the liquid crystal panel stored in the memory unit 430 is transmitted as the DDC information to the graphic source unit 310 via the serial buses 411 and 412, and the graphic source unit ( 310 interprets this information, and transmits various display signals corresponding to the analysis result to the liquid crystal panel display module 400 through predetermined cables 311 and 312.

At this time, unlike the prior art, the display characteristic information of the liquid crystal panel is included in the DDC information shared between the graphic source unit 310 and the memory unit 430 of the liquid crystal panel display module 400. In this case, the display characteristic information of the liquid crystal panel may be changed by a user through a predetermined application program, and the changed information is updated again in the memory unit 430. When the liquid crystal display is turned on again, the memory unit 430 is changed. The graphic source unit 310 is to fetch and interpret the information as updated in the. That is, the user may adjust the input timing directly from the graphic source unit (PC, other display system) 310 by recording the optimum condition suitable for the liquid crystal panel to the graphic source 300.

Here, the display characteristic information of the liquid crystal panel which can be changed by the user through a predetermined application program includes screen display (luminance, gamma, flicker, etc.) information displayed on the FRC, I / O format, and other screens as described above. have. In particular, even the blanking time existing in a video signal that is a standard can be adjusted, so that the liquid crystal display module 400 operates by receiving a signal of a new standard different from the VESA standard signal.

That is, as shown in FIG. 3, the conventional display signal generated by the graphic source unit 310 includes a synchronization signal portion ⓐ, a back porch ⓑ, a portion ⓒ on which image data is loaded, and a front porch. (Ⓓ), the back porch (ⓑ) is characterized in that slightly longer than the front porch (ⓓ). On the other hand, when the blanking time is adjusted according to an embodiment of the present invention, as shown in FIG. 4, the portion ⓖ containing the image data becomes relatively long, and the remaining synchronization signal portion ⓔ and the back porch ⓕ. ), And the front porch (ⓗ) and the like remain only as much as necessary for signal processing for driving the liquid crystal panel, and as narrow as possible. In the above, the user adjusting the blanking time through a predetermined application or the like means that the standard information of the display signal, that is, the portion (ⓖ) on which the image data is loaded, the synchronization signal portion (ⓔ), the back porch (ⓕ), and By defining the time for the front porch (ⓗ) and the like, the graphic source unit 310 generates a display signal of a new standard.

As described above, when the new display characteristic information is updated in the memory unit 430, the graphic source unit 310 fetches and interprets the information to generate a display signal corresponding to the information and transmits the same to the liquid crystal panel display module 400. Done. At this time, the transmitted display signal is also shared with the D / A converter 420 and the timing controller 440 through the serial buses 411 and 412, so that the timing controller 440 is an image signal required to drive the liquid crystal panel. And various control signals are generated and supplied to the corresponding circuits of the PCB module along the wiring 441. The D / A converter 420 is also controlled by the timing controller 440 according to the display characteristic information stored in the memory unit 430 to convert D / A digital data on states such as gamma, flicker, and luminance. Thus, the circuit 421 is supplied to each corresponding circuit of the PCB module along the wiring 421.

As described above, when the user adjusts screen display (luminance, gamma, flicker, etc.) data indicating the display state of the screen through a predetermined application program, the existing OSD function is also digital without an additional option board such as an A / D board. Since it can implement | achieve by a process, the gamma efficiency inherent in a liquid crystal panel can be utilized for the whole area. That is, as shown in Fig. 5, when using an option board such as a conventional A / D board, the gray level near the highest gray level compared to the reference gamma change (R) when adjusting the bright (A) due to the characteristics of the circuit. When the value is lost and the contrast is adjusted (B), the value of the gray level near the lowest gray level is lost. As shown in FIG. 6, when digital processing is performed according to an embodiment of the present invention, the brightness is adjusted (C). In addition, even if the contrast is adjusted (D), the gamma change close to the reference gamma change (R) is maintained, so that the display ability of the liquid crystal panel can be utilized to the maximum.

On the other hand, although the user can realize by adjusting the display characteristic information of the liquid crystal panel indicating the display state of the screen through a predetermined application, etc., this can be realized outside the liquid crystal display as the OSD function is supported in all monitors. It can also be realized in combination with allowing a user to input predetermined data by providing a predetermined key.

As described above, according to an embodiment of the present invention, in the liquid crystal display device which receives and processes a display signal output from the graphic source unit 310 via a serial bus, the graphic source unit 310 is serial By fetching and analyzing the display characteristic information of the liquid crystal panel from the liquid crystal panel display module 400 through the bus, a display signal of a corresponding new standard can be output. Here, the display characteristic information of the liquid crystal panel may be changed by a predetermined signal output from the graphic source unit 310 to the serial bus in response to a user inputting predetermined data using a predetermined program. The user can also change the data by inputting predetermined data using a predetermined key provided outside the liquid crystal panel display.

Description of the liquid crystal display device according to the embodiment of the present invention described above, in addition to the liquid crystal display device, a general flat panel display device such as a plasma display device (PDP) or an organic EL display device having a similar driving method on a PCB module. The present invention may be applied as it is, and the present invention may be variously modified and implemented without departing from the scope of the following claims.

As described above, in driving the flat panel display device according to the present invention, not only the increase in cost and the like caused by the use of the option board is eliminated, but also the occurrence of jitter and the like due to the mismatch of interface conditions can be suppressed as the source. Can be.

Then, the display graphics card or the display source fetches the I / O format information through the serial bus or I ² C bus of the interface cable connector such as DVI or D-SUB to fetch the driving conditions of the flat panel to interface the I / O. By finding the optimal conditions, or by specifying the I / O timings required by the user's adjustment or display source, the settings can be sent back to the flat panel at the optimal conditions to set the display timings required by the display source. It is possible to support graphics signals under any of the standard timing conditions. In particular, when the same display frequency and the same frame frequency, the driving frequency of the flat panel can be driven at a frequency lower than the Besa standard, and if the frequency is lowered, the charging time for the pixel display becomes longer due to the characteristics of the flat panel. There is a time margin for data processing, thereby improving the display characteristics.

In addition, if the optimum driving condition timing of the flat panel should be different from the VESA standard signal, or if the standard signal is slightly different depending on the manufacturer, such a flexible timing can be used for the timing controller's serial bus (I ² C bus, Input timing and output timing can be adjusted freely by SPI bus, 3-WIRE bus, etc. interface, and the data setting values are stored in memory that stores DDC (Digital Data Communication) display information to share timing information. In this way, accurate information of I / O can be stored, updated continuously, and continuously adjusted even if the environment changes, so that there is no additional option system (Scaler, DSP, A / D board with FRC function, etc.) Enables control of DDC display information by changing drive conditions, resulting in timing margins for monitor products It is possible to greatly secure the characteristics for.

In addition, among the display characteristics, gamma generates a fixed voltage externally by a resistance or voltage division method, thereby fixing gamma to a target value. Because of this, if the contrast or the brightness is adjusted by using an A / D board or other intermediate interface, gamma adjustment of the entire gray level cannot be made. The voltage is freely set by the serial bus, so By adjusting it to the desired value without change, it is possible to adjust while using the luminance efficiency of the flat panel 100%.

In addition, user-adjusted values or values set according to the requirements of graphic sources are stored in a storage device such as a memory shared through a serial bus so that the status and information of the monitor product can be shared and adjusted. It is possible to load / reload so that optimal display characteristic information can be managed.

Claims (7)

delete In the flat panel display for receiving and processing the display signal output from the graphics source unit via a serial bus, A timing control unit which receives a display signal output from the graphic source unit through a serial bus and processes the display signal to output a display signal for driving a flat panel; A memory unit connected to the graphic source unit and the timing control unit through the serial bus and storing display characteristic information of the flat panel; And A D / A converter connected to the graphic source unit and the timing controller through the serial bus and converting an input digital gamma value into an analog gamma value based on display characteristic information of the flat panel; Flat panel display device comprising a. The flat panel display of claim 2, wherein the memory unit is a nonvolatile memory. The flat panel display of claim 2, wherein the display characteristic information of the flat panel includes information on a resolution, a frequency, and a gamma. The method of claim 2, The display characteristic information of the flat panel may be changed by a predetermined signal output from the graphic source unit to a serial bus in response to a user inputting predetermined data using a predetermined program. . The method of claim 2, And the display characteristic information of the flat panel can be changed by a user inputting predetermined data using a predetermined key provided outside the flat panel display. A driving method of a flat panel display device for receiving and processing a display signal outputted from a graphic source unit through a serial bus and displaying the same, Storing display characteristic information of the flat panel display in a memory unit included in the flat panel display; Receiving, by the graphic source unit, display characteristic information of the flat panel from the memory unit through a serial bus; Outputting, by the graphic source unit, a display signal of a new standard to the flat panel display device according to an analysis result of the display characteristic information; Displaying, by the flat panel display, an image based on the display signal of the new standard; Method of driving a flat panel display device comprising a.

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